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Abstract:

A method of heating or cooling a room of a building includes providing
supplemental warmer or cooler air to the room with an inline duct
supplemental heating and cooling device mounted along an air duct that
supplies the room with air from a main furnace or cooling unit associated
with the building. A thermostat is used to set a desired temperature for
the room, and a controller of the supplemental heating and cooling device
is in communication with the thermostat, and activates an electric heater
and/or fan as appropriate to warm or cool the room as needed. When the
device is used to cool the room, the fan may be operated to draw cooled
air through the duct from the main cooling unit and/or from other areas
in the building that are linked via ductwork.

Claims:

1. A method of heating and cooling a room that is primarily heated by a
furnace adapted to supply heat to the room through an air duct, and that
is primarily cooled by a cooling unit adapted to supply cooled air to the
room through the air duct, said method comprising: directing
substantially all of the air from the air duct into a fluid passageway
defined by a housing of a heating and cooling device that is positioned
in-line with the air duct, the housing containing a heater and a fan
disposed in the fluid passageway, whereby substantially all of the air in
the fluid passageway is received from the air duct and is directed
through the heater and the fan; controlling the heater and the fan of the
heating and cooling device with a controller that is in communication
with a thermostat positioned in the room; selecting a desired temperature
in the room at the thermostat; automatically activating the heater with
the controller when the temperature detected in the room by the
thermostat is lower than a threshold minimum temperature corresponding to
the selected desired temperature; automatically activating the fan with
the controller when the temperature detected in the room is lower than
the threshold minimum temperature or higher than a threshold maximum
temperature corresponding to the selected desired temperature;
supplementing the cooling unit associated with the air duct by activating
the fan to draw cooled air through the air duct with the fan when the
temperature detected by the thermostat in the room is higher than the
threshold maximum temperature corresponding to the selected desired
temperature; and discharging substantially all of the air in the fluid
passageway of the heating and cooling device into the room.

2. The method of claim 1, further comprising automatically deactivating
the electric heater when the, temperature detected in the room is
approximately equal to the desired temperature.

3. The method of claim 1, further comprising automatically deactivating
the fan when the temperature detected in the room is approximately equal
to the desired temperature.

4. The method of claim 1, further comprising selectively activating the
electric heater and the fan with a wireless thermostat that is in
wireless communication with the controller.

5. The method of claim 1, further comprising positioning the heating and
cooling device in-line with the air duct by coupling a vibration
insulator sleeve, which includes a hollow fabric member, between the
housing and the air duct.

6. A method of heating and cooling a room that is primarily heated by a
furnace adapted to supply heat to the room through an air duct, and that
is primarily cooled by a cooling unit adapted to supply cooled air to the
room through the air duct, said method comprising: mounting an electric
heating and cooling device in-line with the air duct, the electric
heating and cooling device including an electric heater and a fan
disposed in a fluid passageway defined by a housing that is coupled to
the air duct; directing heated or cooled air, from the furnace or the
cooling unit, through the air duct so that substantially all air passing
from the furnace or the cooling unit through the air duct is directed
through the fluid passageway, the heater, and the fan, so that
substantially all of the air passing through the electric heating and
cooling device is received from only the air duct regardless of whether
either of the fan or the electric heater is operating; adjusting a
thermostat that is in communication with the heating and cooling device
to select a desired temperature in the room; detecting a temperature in
the room with the thermostat; automatically activating the electric
heater and the fan when the temperature detected in the room is lower
than the desired temperature, to propel heated air generated by the
furnace and the electric heater to the room through the air duct; and
automatically activating the fan without activating the electric heater
when the temperature detected in the room is higher than the desired
temperature to propel air through the air duct that is at a cooler
temperature than the temperature detected in the room by the thermostat.

7. The method of claim 6, further comprising automatically deactivating
the electric heater when the temperature detected in the room is higher
than or equal to the desired temperature.

8. The method of claim 6, further comprising automatically deactivating
the fan when the temperature detected in the room is substantially equal
to the desired temperature.

9. The method of claim 6, further comprising selectively activating the
electric heater and the fan with a wireless thermostat that is in
wireless communication with the controller.

10. The method of claim 6, further comprising: detecting a temperature of
air discharged from the heating and cooling device with a discharge air
temperature sensor mounted at the housing; and automatically deactivating
the electric heater when the discharge air temperature sensor detects
that the temperature of the air discharged from the heating and cooling
device is higher than a selectively chosen limit temperature.

11. The method of claim 6, wherein said mounting the electric heating and
cooling device in-line with the air duct comprises coupling a vibration
insulator sleeve, including a hollow fabric member, between the housing
and the air duct.

12. A method of heating and cooling a room that is primarily heated by a
furnace adapted to supply heat to the room through an air duct, and that
is primarily cooled by a cooling unit adapted to supply cooled air to the
room through the air duct, said method comprising: positioning an
electric heating and cooling device in-line with the air duct, the
electric heating and cooling device including a heater and an electric
fan disposed in a fluid passageway defined by a housing; directing
substantially all of the air passing from the furnace or the cooling unit
through the air duct through the fluid passageway, the heater, and the
fan; selectively adjusting a thermostat that is in communication with the
heating and cooling device to a temperature desired in the room;
detecting a temperature in the room with the thermostat; automatically
activating the heater and the fan when the temperature detected in the
room is detected by the thermostat as being lower than a threshold
minimum temperature corresponding to the desired temperature;
automatically activating the fan, without activating the heater, when the
temperature detected in the room is higher than a threshold maximum
temperature corresponding to the desired temperature, to propel air
through the air duct that is at a cooler temperature than the temperature
detected in the room by the thermostat.

13. The method of claim 12, further comprising automatically deactivating
the electric heater when the temperature detected in the room is higher
than or substantially equal to the desired temperature.

14. The method of claim 12, further comprising automatically deactivating
the fan when the temperature detected in the room is substantially equal
to the desired temperature.

15. The method of claim 12, further comprising selectively activating the
electric heater and the fan with a wireless thermostat that is in
wireless communication with the electric heating and cooling device.

16. The method of claim 15, further comprising selectively activating the
electric heater and the fan with a controller that is in wireless
communication with the wireless thermostat.

17. The method of claim 12, wherein said positioning an electric heating
and cooling device in-line with the air duct comprises coupling a
vibration insulator sleeve, including a hollow fabric member, between the
housing and the air duct.

Description:

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a division of U.S. patent application Ser. No.
12/201,101, filed Aug. 29, 2008, which claims the benefit of U.S.
provisional application, Ser. No. 60/970,102, filed Sep. 5, 2007, both of
which are hereby incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

[0002] The present invention relates generally to supplemental heating and
cooling devices, especially for forced air heating systems in buildings.

BACKGROUND OF THE INVENTION

[0003] It is known to provide auxiliary or supplemental heating devices in
rooms that tend to be cooler than the rest of a home or building, or in
rooms in which a higher temperature is desired., Such supplemental
heaters may be placed directly in the room or may be positioned in an air
duct that is adapted to supply heat from the home's standard or
traditional furnace to the room.

[0004] However, some of these types of devices must be manually activated
and deactivated. Even if such a device is adapted to be activated
automatically, the components of the device, such as a heater or a fan,
etc., are typically not adapted to be activated and deactivated
individually. Further, these types of devices are not adapted to also
assist in cooling the room-when the temperature in the room is warmer
than desired. Additionally, with respect to devices adapted to be mounted
in an air duct, several safety issues and fire hazards can arise, such as
overheating of the air in the duct or of the heating device itself,

SUMMARY OF THE INVENTION

[0005] The embodiments of the present invention provide an electric
heating and cooling device adapted to supplement a standard or
traditional furnace or cooling system that supplies heated or cooled air
to a room through at least one air duct extending therefrom. The heating
and cooling device is adapted to be at least partially mounted in the air
duct and includes an electric heater, a fan adapted to blow air through
the duct, and a housing for containing the electric heater and fan. The
heating and cooling device also includes a thermostat for selecting a
desired temperature in the room and detecting a temperature in the room.
A control is electrically connected to the thermostat and to the electric
heater and fan for activating and deactivating the electric heater and
fan based on input from the thermostat. The control automatically
activates the electric heater when a temperature detected in the room is
lower than the desired temperature. Further, the control automatically
activates the fan when the temperature detected in the room is higher or
lower than the desired temperature.

[0006] The heating and cooling device also includes a discharge air
temperature sensor adapted to deactivate the electric heater when the
temperature of air being discharged from the air duct is higher than a
selectively chosen limit temperature, which may be approximately 70
degrees Celsius. Additionally, a safety temperature limit switch is
included to deactivate the electric heater when the temperature of the
electric heater is higher than a selectively chosen limit temperature,
which may be approximately 111 degrees Celsius. The safety temperature
limit switch is automatically reset to allow activation of the electric
heater when the electric heater cools to a temperature below the limit
temperature.

[0007] Optionally, the control deactivates the electric heater and fan
when the temperature detected by the thermostat in the room is higher
than or equal to the desired temperature. The control may also deactivate
the fan when the temperature detected in the room by the thermostat is
equal to the desired temperature.

[0008] In addition to the discharge air temperature sensor and safety
temperature limit switch, and in the case that these two safety devices
fail to prevent overheating of the device, the heating and cooling device
may include a fusible link, or thermal cut out, which physically breaks
or otherwise interrupts the electric current from or between the control
to the electric heater and the fan when the temperature of the electric
heating and cooling device exceeds a selectively chosen limit
temperature, which may be approximately 1 to 5 degrees Celsius higher
than that of the safety temperature limit switch, such as, for example,
113 degrees Celsius. The heating and cooling device is not operable when
the fusible link is broken. Optionally, an automatically resettable
temperature limit control detects radiant and/or convective heat from the
heater, and may be used in place of the safety temperature limit switch
and fusible link. The automatically resettable temperature limit control
deactivates the electric heater when the temperature at the limit control
is higher than a selectively chosen limit temperature, which may be
approximately 65 degrees Celsius.

[0009] Optionally, the control may comprise an electrical circuit on a
circuit board. A conduit may be attached or mounted to the housing of the
device for containing wiring adapted to electrically connect the electric
heater and the fan to the control or circuit board.

[0010] Optionally, the heating and cooling device may be connected to the
air duct via a vibration insulator sleeve that includes a cylindrical
hollow fabric member for absorbing sound and vibration from the device.
The vibration insulator sleeve includes a coated fabric, such as vinyl or
fiberglass fabric coated with silicone, polychloroprene, or
chlorosulfonated polyethylene, that is looped and heat-sealed to form the
cylindrical hollow fabric member. The sleeve may be flexible and axially
collapsible to facilitate installation of the sleeve and the heating and
cooling device in a gap in an air duct.

[0011] According to another embodiment of the invention, a method of
heating and cooling a room is provided. The room is primarily heated by a
furnace that is adapted to supply heated air to the room through at least
one air duct. The method includes mounting an electric heating and
cooling device in the at least one air duct, the electric heating and
cooling device including an electric heater, a fan, and a housing for
containing or supporting the electric heater and fan. The method further
includes selectively adjusting a thermostat, which is electrically
connected to or in communication with the heating and cooling device, to
a temperature desired in the room, and detecting a temperature in the
room. The electric heater and fan are automatically activated when the
desired temperature is higher than the temperature detected in the room.
The fan is also automatically activated when the desired temperature is
lower than the temperature detected in the room to blow cool air, or air
that is at a temperature lower than the air in the room, through the air
duct into the room.

[0012] Further, the method may include deactivating the electric heater
when the desired temperature sensed by the thermostat is lower than or
equal to the temperature detected in the room and deactivating the fan
when the desired temperature is equal to the temperature detected in the
room.

[0013] Optionally, a discharge air temperature sensor may deactivate the
electric heater when a temperature of air discharged from the air duct is
higher than a selectively chosen limit temperature, which may be
approximately 70 degrees Celsius.

[0014] Further, a safety temperature limit switch may deactivate the
electric heater when a temperature of the electric heater exceeds a
selectively chosen limit temperature, which may be approximately 111
degrees Celsius. The safety temperature limit switch automatically resets
to allow the electric heater to operate when the electric heater cools to
a temperature below the limit temperature.

[0015] Optionally, the method may include breaking a fusible link to
interrupt the electric current from a control adapted for activating and
deactivating the electric heater and the fan. The fusible link is
automatically broken when the electric heating and cooling device exceeds
a selectively chosen limit temperature, which may be approximately 113
degrees Celsius. The electric heating and cooling device is prevented
from operating after the fusible link is broken, such that the fusible
link must be replaced to allow the electric heating and cooling device to
operate.

[0016] Thus, the inline duct supplemental heating and cooling device of
the present invention provides heated and/or cooled air, and/or air at a
temperature lower than that in the room to a room in a building that is
typically cooler or warmer than the remaining rooms in the building. For
example, the device provides supplemental heated air to rooms that are a
great distance or remote from the furnace positioned at the end of the
heating duct, or to rooms that are larger or contain a number of windows
and are, therefore, more difficult to heat. Further, the electric heater
and fan are adapted to be activated and deactivated individually, such
that the device is adapted to operate in "fan only" mode to increase air
circulation to assist in cooling the room when the temperature in the
room is warmer than desired. Because the device is adapted to use the
existing duct work of a building, additional ducts are not required. In
addition, the device may include three levels of protection, i.e., three
separate safety devices, to prevent overheating of heater air or the
device itself, even in the case of circuit board failure. The device may
be mounted to an existing air duct via a vibration insulator sleeve that
is flexible and collapsible, and which absorbs sound and vibration from
the device to provide quiet operation and facilitate installation.

[0017] These and other objects, advantages, purposes and features of the
present invention will become apparent upon review of the following
specification in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is a schematic view of a system of heating and cooling a
room, including a heating and cooling device according to the present
invention;

[0019] FIG. 2 is a side elevation of the heating and cooling device of
FIG. 1;

[0020] FIG. 3 is a front elevation of the heating and cooling device of
FIGS. 1 and 2;

[0021] FIG. 4 is a is a side elevation of another heating and cooling
device according to the present invention;

[0022] FIG. 5 is a front elevation of the heating and cooling device of
FIG. 4;

[0023] FIG. 6 is a rear elevation of the heating and cooling device of
FIGS. 4 and 5;

[0024] FIG. 7 is a circuit diagram of a circuit adapted to control the
heating and cooling device of FIGS. 2-6;

[0025] FIG. 8 is a schematic view of a method of heating and cooling a
room, according to the present invention;

[0026] FIG. 9 is a perspective view of another heating and cooling device
according to the present invention; and

[0027] FIG. 10 is a sectional side elevation of the heating and cooling
device of FIG. 9, including a vibration insulator sleeve.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Referring now to the drawings and the embodiments illustrated
therein, a system 10 for heating and cooling or conditioning a space,
such as a room in a home or other building, includes an electric heating
and cooling device 12 adapted to supplement a traditional or standard
furnace 14 or air conditioner 14' (FIG. 1). Heating and cooling device 12
is adapted to be at least partially mounted in an air duct, such as air
duct 16 of a forced air duct system, which extends from furnace 14 or a
cooling unit 14' for transferring heated or cooled air to a room 22.
Device 12 is especially useful for rooms that may be remote from furnace
14 (or an air conditioning unit 14' that may be connected to and use duct
system 16) at or near the end of duct system 16, where heating and/or
cooling is/are less efficient than for rooms closer to furnace 14 and/or
cooling unit 14'. Device 12 may also be useful for rooms that are large
or that have a number of windows, which may make such rooms difficult to
heat and/or cool.

[0029] As shown in FIG. 2, heating and cooling device 12 includes an
electric heater assembly or heater 28 having a plurality of resistance
type heating devices 29 and a fan 30 adapted to blow heated or cooled air
from furnace 14 or cooling unit 14' through duct 16. Device 12 also
includes a housing 34 that contains or supports heater 28 and fan 30
therein. A thermostat 24 (FIGS. 1, 2, and 4) is provided for selecting a
desired temperature in room 22 and detecting a temperature in room 22 and
is connected to a control 36 for device 12, as explained more fully
below. Control 36 is electrically connected to thermostat 24 via a wire
26 or via a wireless connection, and to heater 28 and fan 30, for
activating and deactivating one or more of heater 28 and fan 30 based on
input from thermostat 24. For example, when the actual or current
temperature detected in room 22 by thermostat 24 is lower than the
desired temperature set on thermostat 24, control 36 automatically
activates heater 28 and fan 30, to blow heated air from both furnace 14
and heater 28 through duct 16 into room 22. Control 36 also automatically
activates fan 30 when the temperature detected in room 22 is higher than
the desired temperature set on thermostat 24, i.e., when heater 28 is not
activated, such that fan 30 blows air through duct 16 to ventilate and
cool room 22, especially when system 10 includes an air conditioning unit
14'.

[0030] Heating and cooling device 12 also includes safety devices to
prevent overheating of both heater 28 and the air in duct 16.
Specifically, a discharge air temperature sensor 40 positioned in duct 16
downstream from fan 30 is connected to control 36 and is adapted to
deactivate heater 28 when the temperature of air being discharged from
duct 16 is higher than a selectively chosen limit temperature, which may
be set in the range of approximately 70 degrees Celsius. Discharge air
temperature sensor 40 may be of the type sold under part number
F1107025ACFA06E by Cantherm, having a place of business at 8415 Mountain
Sights Avenue, Montreal (Quebec), H4P 2B8 Canada
(http://www.cantherm.com). Heating and cooling device 12 also includes a
temperature limit control or safety temperature limit switch 42 adapted
to deactivate heater 28 when the temperature immediately adjacent heater
28 reaches a certain temperature that is selectively chosen as a limit
temperature, which may be set in the range of approximately 111 degrees
Celsius. Safety temperature limit switch 42 is adapted to automatically
reset when the temperature immediately adjacent heater 28 cools to a
temperature below the limit temperature, to allow or resume operation of
heater 28. Thus, safety temperature limit switch 42 is not required to be
manually reset or replaced once it has been activated. Limit switch 42
may be of the type sold by Holmes, Inc., having a place of business at
1605 George Dieter #688, El Paso, Tex. 79936
(http://www.holmesproducts.com).

[0031] Housing 34 may be formed from galvanized sheet metal, polyvinyl
coated ductwork or other similar material and may be formed in any
suitable shape adapted to contain heater 28 and fan 30. Housing 34 is
preferably adapted to be mounted in a standard air duct, such as a
standard six inch, seven inch, or eight inch round, metal supply duct.
For example, housing 34 may be formed from six inch polyvinyl coated
ductwork (PCD) spiral pipe, or from any . other material adapted to
withstand heat from heater 28. In the illustrated embodiment, housing 34
is generally cylindrical and hollow, and contains open ends, such that
housing 34 is adapted to allow air to flow therethrough. For example, as
shown in FIG. 1, heated air flowing from furnace 14 flows through a
connection corner duct 18 into duct 16, and through housing 34 of heating
and cooling device 12, and continues to flow through duct 16 in a
direction A toward supply register 20 in room 22. Housing 34 is mounted
in duct 16 such that air flows in direction A first toward heater 28 and
then into fan 30 and toward supply register 20 (FIGS. 2 and 4).

[0032] Heater 28 of heating and cooling device 12 may be any suitable
heating device adapted to be mounted or at least partially positioned or
contained in housing 34. For example, heater 28 may be a selectable 500,
1000, or 1500 watt open coil, resistance type, electric heating device or
assembly, which are known in the art and which may be supplied by Holmes,
Inc., having a place of business at 1605 George Dieter #688, El Paso,
Tex. 79936 (http://www.holmesproducts.com). Heater 28 may be a standard
heating device or may be customized for optimal performance in heating
and cooling device 12,

[0033] Fan 30 may be any suitable fan adapted to blow air through duct 16
and adapted to be at least partially mounted or positioned in housing 34.
Like heater assembly 28, fan 30 may be customized to work with heater 28
to provide optimal performance of heating and cooling device 12. In the
illustrated embodiment of FIGS. 2 and 3, fan 30 is a variable,
multi-speed circulating rotary fan having a diameter adapted to fill 90
to 95% of the diameter of housing 34. For example, the blades of fan 30
may have a diameter of 5.5 inches when being installed in a six inch
round supply duct. Fan 30 may be powered by any standard C-frame motor 32
via shaft 33 and may be of the type sold under model number FP-108CXS1 by
Commonwealth, having a place a business at No. 4 Alley 6 Lane 174
HSIN-Ming Rd., Nei-Hu, Taipei, Taiwan R.O.C.
(http://www.cic-commonwealth.com.tw). As shown in FIGS. 4 and 6, in
another embodiment that will be discussed in more detail below, fan 130
comprises a tube-axial fan.

[0034] The fan of the heating and cooling device 12 is adapted to assist
in both the heating and cooling of the room. As shown in FIG. 1, fan 30
is positioned or mounted in housing 34 to assist in blowing heated air
from both heater 28 and furnace 14 through duct 16 in a direction A
toward a supply register 20 in room 22. Similarly, when a cooling unit
such as air conditioning unit 14' is connected to duct 16, fan 30 assists
in blowing cooled air, at a temperature cooler than the temperature of
the room 22, through duct 16. Further, fan 30 is adapted to be activated
on its own, i.e., when heater 28, furnace 14 and/or air conditioning unit
14' are all deactivated or when a furnace or air conditioning unit is not
included in the system. For example, control 36 may cause fan 30 to
automatically operate in "fan only" mode when the temperature detected in
the room is higher than the desired temperature set on thermostat 24, to
ventilate and increase air circulation in room 22 to assist in cooling
room. 22 to the desired temperature. Thus, control 36 may automatically
activate fan 30 to assist the operation of either a furnace 14 or an air
conditioning unit 14', or may activate fan 30 to operate on its own to
ventilate room 22 or improve air circulation in room 22.

[0035] Control 36 may be any suitable electrical control circuit, such as
a circuit board, which may be specially configured or customized to
control heating and cooling device 12. As discussed above, control 36
functions to regulate the operation or the activation and deactivation of
heater 28 and fan 30 based on input from thermostat 24, which may
comprise any standard thermostat commonly known in the art, such as a 24
V.A.C. heating and/or cooling thermostat. Optionally, and to facilitate
installation, a wireless thermostat may be used, such as the T8665A
Chronotherm® IV Deluxe Programmable Wireless Thermostat, supplied by
Honeywell, having a place of business at 1985 Douglas Drive North, Golden
Valley, Minn. 55422 (www.honeywell.com/yourhome). Control 36 compares the
desired temperature set on thermostat 24 with the actual or current
temperature detected in room 22 and activates heater 28 and fan 30 until
the desired warmer temperature is reached, and also deactivates the
heater when the temperature detected in the room is higher than or equal
to the desired temperature, as discussed above. Because the fan assists
in both heating and cooling or ventilating room 22, control 36
deactivates fan 30 only when the temperature detected in the room is
equal to the desired temperature set on thermostat 24.

[0036] Optionally, other thermostats may be used without departing from
the spirit and scope of the present invention. For example, a two-stage
thermostat may be used which initially activates the heating and cooling
device to raise or lower the temperature of a room, and if additional
heating or cooling is needed to bring that room to the desired room
temperature, the thermostat activates the building's main furnace or air
conditioner as needed. Optionally, two or more heating and cooling
devices may be installed in different air ducts serving the same room,
and controlled by a single thermostat.

[0037] As shown in FIG. 7, which illustrates a circuit diagram of control
36, the action of switching power from R circuit 48 to W circuit 50 will
energize relay 1 (designated by numeral 52) to switch power to the 0.5 kw
terminal 54 and 1 kw terminal 56 to send power to heater 28, assuming
that all three safety limit switches are closed. Such an action would not
be permitted if one of the safety limit switches is open. Simultaneously,
while R circuit 48 and W circuit 50 are closed, relay 2 (designated by
numeral 58) is energized, thus switching power to the fan L1 out terminal
60 to send power to fan 30. Power to fan 30 may also be provided by the
action of switching power from R circuit 48 to Y/G circuit 62, which will
energize relay 2 (58) to switch power to the fan L1 out terminal 60 to
send power to fan 30.

[0038] Optionally, a cover or enclosure 38 may be provided to protect the
control or circuit board. As shown in FIGS. 2 and 3, control 36 is
enclosed or contained within control enclosure 38, which may be part
number 50-1289-1, supplied by Magnecraft, having a place of business at
191 Waukegan Rd, Ste. 206, Northfield, Ill. 60093-2743
(http://www.magnecraft.com).

[0039] Further, in addition to the two safety devices discussed above,
namely, discharge air temperature sensor 40 and safety temperature limit
switch 42, heating and cooling device 12 may also include a thermal
cut-out or fusible link 44, which, when broken, physically breaks or
otherwise, interrupts the electric current from control 36 to heater 28
and fan 30. Fusible link 44 may be set to break when the temperature
exceeds a selectively chosen limit. temperature, which may be
approximately 1 to 5 degrees Celsius higher than that of the safety
temperature limit switch, such as, for example, approximately 113 degrees
Celsius. Fusible link 44 disables heating and cooling device 12 to
prevent overheating and a possible fire hazard in the case of circuit
board malfunction or failure, for example. When fusible link 44 is
broken, heating and cooling device 12 is unable to operate until the
broken fusible link has been replaced. Thus, unlike safety temperature
limit switch 42, fusible link 44 is not adapted to be automatically reset
when heating and cooling device 12 cools to a temperature below the limit
temperature. Typically, fusible link 44 is selected to interrupt the
electrical current to heater 28 and fan 30 at a temperature approximately
1 to 3 degrees higher than limit switch 42 and operates as an ultimate
fail-safe shut off. Fusible link 44 may be supplied by Holmes; Inc.,
having a place of business at 1605 George Dieter #688, El Paso, Tex.
79936 (http://www.holmesproducts.com).

[0040] Optionally, as shown in FIG. 3, heating and cooling device 12 may
include a conduit 46 adapted to contain the wiring that electrically
connects the electric heater and fan to the control or circuit board. In
the illustrated embodiment, conduit 46 is attached or mounted at one end
to housing 34 and extends around or about housing 34 to control enclosure
38.

[0041] Alternately, in another embodiment of the invention, the wiring
from the heater and the fan may lead directly from the housing into
control enclosure 38, such that an external conduit is not required. For
example, as shown in FIGS. 4-6, a heating and cooling device 112 includes
a housing 134 and a control enclosure 138 that is mounted or attached
thereto. Wiring from a heater 128 having electrical resistance coils 129
and a tube-axial fan 130, which are both mounted in the housing, leads
directly from housing 134 into control enclosure 138, which houses or
contains control 136.

[0042] Tube-axial fan 130 is different from fan 30 described above because
tube-axial fan 130 is mounted in a tube or cylinder 132 to increase the
efficiency of the fan. Heating and cooling device 112 may be otherwise
similar to heating and cooling device 12, described above.

[0043] Optionally, and with reference to FIGS. 9 and 10, a heating and
cooling device 212 is adapted to supplement a traditional or standard
furnace or air conditioner and includes a fan unit 230 positioned
downstream of a heater unit 228. Fan unit 230 and heater unit 228 are
positioned inside a housing 234 and controlled by a controller 236
mounted to an exterior surface of housing 234 via fasteners 237.
Optionally, a vibration insulator sleeve 264 (FIG. 10) is coupled to one
or both ends of housing 234 to facilitate mounting of device 212 to a
duct and to isolate noises produced by device 212.

[0044] Fan unit 230 includes an anti-crush ring 266 surrounding fan blades
268 to protect the fan blades from accidental damage or seizing due to
improper handling prior to installation of device 212. An electric motor
232 is supported by support members 266a within anti-crush ring 266, and
is operable in response to controller 236 to drive fan blades 268.
Anti-crush ring 266 may be an aluminum casting or other formed metal
member that sufficiently resists accidental compression of the housing
234 in the vicinity of fan unit 230. A discharge air temperature sensor
240 is mounted to one of support members 266a and functions in
substantially the same way as air temperature sensor 40, described above.
Optionally, other sensors or limiters, such as a safety temperature limit
switch and/or a fusible link, such as those described above, may be used
to limit or prevent overheating or overvoltage conditions.

[0045] Heater unit 228 is positioned upstream of fan unit 230, and may
function in substantially the same manner as electric heater 28. Heater
unit 228 includes a plurality of radially-arranged and spaced fins or
louvers 229 with holes 229a for supporting a plurality of resistance type
heating devices or heater wires (not shown in FIGS. 9 and 10, for
clarity) that are substantially the same as resistance type heating
devices 29, described above, and arranged substantially as shown with
reference to coils 129 of FIGS. 4 and 5. By positioning heater unit 228
upstream of fan unit 230, heater unit 228 is exposed to relatively
non-turbulent air from the duct, rather than relatively turbulent air
from fan blades 268, in order to more uniformly transfer heat from the
heater wires to the air that is drawn past the wires by fan unit 230.

[0046] A safety temperature limit switch or temperature limit control 244
is positioned on or adjacent one of fins 229 for detecting radiant heat
and/or air temperature immediately downstream of the heater wires, and
may serve to deactivate the heater wires if the air temperature exceeds a
selected limit, such as about 65 degrees Celsius. Temperature limit
control 244 may serve substantially the same function and be used in
place of fusible link 44 and safety temperature limit switch 42, whereby
temperature limit control 244 interrupts the electric current from
control 236 to heater unit 228 and/or fan unit 230 when excessive radiant
and/or convective heat is detected, such as due to a failed fan unit 230.
Temperature limit control 244 may be a fully automatically resettable
limit controller that permits resumed operation of device 212 after the
temperature detected at control 244 drops to an acceptable level.

[0047] Optionally, two or more electrically isolated sets of heating wires
are provided to permit selecting a desired heat output of heater unit
228. For example, heater unit 228 may operate with only a relatively
low-powered set of heater wires or only a relatively high-powered set of
heater wires. The desired heater wires may be selected by installing a
jumper or toggling a switch on controller 236. Optionally, both sets of
heating wires may be operated simultaneously to maximize the heat output
of heater unit 228.

[0048] Controller 236 includes an electronic control or circuit board 270
that is mounted to housing 234 and may be electrically isolated therefrom
by spacer lugs 272. Circuit board 270 includes a low-voltage side 270a
for receiving signals from a thermostat and for handling controller
functions, and a high-voltage side 270b for handling the heater and fan
power. High-voltage side 270b is separated from low-voltage side 270a by
a plate or riser 274 that physically separates the sides to reduce or
prevent damage to the low-voltage side 270a caused by accidental
electrical contact with the high-voltage side 270b. A cover or enclosure
238 surrounds circuit board 270 and further protects it from outside
physical and electrical damage.

[0049] Vibration insulator sleeve 264 (FIG. 10) isolates air ducts, such
as air duct 16, from vibration and noises generated by heating and
cooling device 212 and facilitates installation of device 264 into an air
duct. Sleeve 264 includes a hollow cylinder 276 of fabric and a coupling
ring 278 on either end of the fabric cylinder 276. Fabric cylinder 276
may be fabricated from a sheet of vinyl or fiberglass fabric coated with
silicone, chlorosulfonated polyethylene (such as Hypalon®); or
polychloroprene (such as Neoprene®), for example, such as a
Hardcast® brand flexible duct connectors, available from Carlisle
Coatings and Waterproofing Inc., having a place of business at 900
Hensley Lane, Wylie, Tex. 75098 (http://www.hardcast.com). Fabric
cylinder 276 is generally compliant and resilient to absorb much of the
vibration and noise produced by heating and cooling device 212 and to
provide quieter operation, and may be used on either side (i.e., one or
both sides) of the device to maximize the sound and vibration isolation.
In addition, fabric cylinder 276 is axially compressible to reduce the
length or axial dimension of the device 212 when it is equipped with one
or more sleeves 264, to facilitate installation and removal of device 212
from an air duct. Fabric cylinder 276 may have sufficient resilience to
extend itself axially when compressive loads are released.

[0050] Fabric cylinder 276 is formed by rolling the fabric into a
cylindrical shape so that two opposed edge portions overlap, and
heat-sealing the edge portions together to form a substantially air-tight
seam. Coupling rings 278 are joined to the ends of fabric cylinder 276
such as by crimping a portion of each ring onto the fabric, or by gluing,
riveting, or the like. When used in conjunction with heating and cooling
device 212, one of rings 278 of sleeve 264 may be slid and telescoped
into or over housing 234 and fastened or joined to the housing 234 via a
rivetless joint, rivets or other fasteners, welding, or the like, and the
other ring 278 joined to the air duct in a similar manner.

Operation and Method

[0051] A method of heating and cooling a room will now be understood from
FIG. 8. The room is primarily heated by a furnace 14 connected to at
least one forced air duct 16 adapted to transfer heat from the furnace 14
into the room 22. The method includes mounting an electric heating and
cooling device 12, 112, 212 in the at least one air duct 16. The electric
heating and cooling device includes an electric heater 28, 128, 228, a
fan 30, 130, 230, and a housing 34, 134, 234 for containing the electric
heater and the fan, as discussed above. The method also includes
selectively adjusting a thermostat 24 to a temperature desired in the
room and detecting a current or actual temperature in the room.

[0052] When heating and cooling device 212 is equipped with one or more
sleeves 264, the device 212 may be installed in a gap in an existing air
duct by axially compressing fabric cylinder 276 until the outermost rings
278 are positioned in the gap between open ends of the air duct. Device
212 is inserted into the gap, and fabric cylinder 276 is released so that
the outermost rings 278 are urged into or over the open ends of the air
duct. Rings 278 are then fastened to the air duct and electrical
connections are made to controller 236 to complete the installation of
the heating and cooling device.

[0053] According to the method, electric heater 28, 128, 228 and/or fan
30, 130, 230 operate automatically via control 36 in response to input
from thermostat 24 to assist in either heating or cooling the room. For
example, the electric heater and the fan are automatically activated when
the temperature detected in the room is lower than the desired
temperature, to blow heated air generated by the electric heater and the
furnace to the room through the air duct. The fan is also automatically
activated when the temperature detected in the room is higher than the
desired temperature, to blow air through duct 16 to ventilate or increase
air circulation through the room. Optionally, when duct 16 is connected
to an air conditioning unit, fan 30 may be automatically activated to
blow cooled air from the air conditioning unit, which is at a temperature
cooler than that of the room, through the air duct to assist in cooling
the room. Additionally, fan 30 may draw cooler air from other rooms in
the house and the air ducts that feed them, in order to assist in cooling
the room.

[0054] Further, electric heater 28, 128, 228 may be automatically
deactivated when the actual temperature detected in the room is higher
than or equal to the desired temperature in the room. Because fan 30,
130, 230 assists in both heating and cooling or ventilating the room, as
discussed above, the fan may be automatically deactivated only when the
temperature set on the thermostat is equal to the temperature detected in
the room.

[0055] The method preferably includes the activation of safety mechanisms
to prevent overheating of the heating and cooling device and the room to
which it is connected. For example, a discharge air temperature sensor
may be activated to deactivate electric heater 28, 128, 228 when the
temperature of air being discharged from the electric heating and cooling
device is higher than a selectively chosen limit temperature, which may
be approximately 70 degrees Celsius. Additionally, a safety temperature
limit switch may be activated to deactivate the electric heater when the
temperature of the electric heater exceeds a selectively chosen limit
temperature, such as 111 degrees Celsius. The safety temperature limit
switch automatically resets to allow the electric heater to operate when
the electric heater cools to a temperature below the designated or chosen
temperature.

[0056] The method may also include connecting a fusible link in the
electrical circuit to interrupt the electric current from the control to
the electric heater and the fan when the electric heating and cooling
device exceeds a selectively chosen limit temperature, which may be
approximately 113 degrees Celsius. Once the fusible link is broken, the
heating and cooling device is unable to operate. Accordingly, the method
may include replacing the fusible link to again operate the electric
heating and cooling device.

[0057] When heating and cooling device 212 is equipped with one or more
sleeves 264, the device 212 may be installed in a gap in an existing air
duct by axially compressing fabric cylinder 276 until the outermost rings
278 are positioned in the gap between open ends of the air duct. Device
212 is inserted into the gap, and fabric cylinder 276 is released so that
the outermost rings 278 are urged into or over the open ends of the air
duct. Rings 278 are then fastened to the air duct and electrical
connections are made to controller 236 to complete the installation of
the heating and cooling device.

[0058] Thus, the embodiments presented herein provide an electric heating
and cooling device adapted to supplement a home's traditional heating
and/or cooling system. The device provides supplemental heated air to a
room that is difficult to heat and is adapted to assist an air
conditioning unit in providing cooled air to a room that is typically
warmer than the rest of the rooms in a building. Further, the device is
adapted to operate in "fan only" mode to ventilate a room when the
temperature in the room is warmer than desired. Installation of the
device is simplified in that the device is adapted to be mounted in the
existing duct work of a home, such that additional ducts are not
required. In addition, the device includes three separate safety devices
to prevent overheating.

[0059] Changes and modifications to the specifically described embodiments
may be carried out without departing from the principles of the present
invention, which is intended to be limited only by the scope of the
appended claims as interpreted according to the principles of patent law
including the doctrine of equivalents.